Mobile wireless communications device with diversity wireless local area network (LAN) antenna and related methods

ABSTRACT

A mobile wireless LAN communications device may include a portable, handheld housing, and a wireless LAN transceiver carried by the housing. A polarization diversity wireless LAN antenna may be included for cooperating with the wireless LAN transceiver to communicate over a wireless LAN. The polarization diversity wireless LAN antenna may include a first antenna element coupled to the wireless LAN transceiver having a first shape and a first polarization, and a second antenna element coupled to the wireless LAN transceiver having a second shape different from the first shape. The second antenna element may also have a second polarization different from the first polarization.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of Ser. No. 10/924,276 filed Aug. 23,2004 now U.S. Pat. No. 7,353,013, the entire disclosure of which ishereby incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to the field of communications systems,and, more particularly, to wireless communications systems and relatedmethods.

BACKGROUND OF THE INVENTION

Computers are often connected together as part of a Local Area Network(LAN). The LAN permits computers to share data and programs with oneanother. Many typical LANs are based upon physical connections betweenindividual computers and a server, for example. The connections may betwisted pair conductors, coaxial cables, or optical fibers, for example.

There is also another class of LAN based upon wireless communication tothe individual computers. A wireless LAN is not restricted to havingphysical connections to the individual computers. Accordingly, originalinstallation may be simplified. Additionally, one or more of thecomputers may be used in a mobile fashion. In other words, the user mayuse a laptop computer and move from place to place while still beingconnected via the wireless LAN.

Various standards have been created to define operating protocols forwireless LANs, such as the IEEE 802.11 and Bluetooth standards. The IEEE802.11 standard, for example, defines the protocol for several types ofnetworks including ad-hoc and client/server networks. An ad-hoc networkis a network where communications are established between multiplestations in a given coverage area without the use of an access point orserver. The standard provides methods for arbitrating requests to usethe medium to ensure that throughput is maximized for all of the usersin the base service set. Another widely used wireless LAN format isBluetooth.

The client/server network uses an access point that controls theallocation of transmit time for all stations and allows mobile stationsto roam from one access point to another. The access point is used tohandle traffic from the mobile radio to the wired or wireless backboneof the client/server network. This arrangement allows for pointcoordination of all of the stations in the basic service area andensures proper handling of the data traffic. The access points routedata between each station and other wired/wireless stations, or to andfrom the network server (i.e., a base station). Of courser two or moreLANs may be interconnected using wireless LAN devices at respectiveaccess points. This may be considered a network bridge application.

One of the challenges of wireless LAN implementation is designingsuitable antennas that can provide desired performance characteristics,yet are relatively small in size to fit within mobile devices. Forexample, with wireless LAN devices such as laptop computers, it isdesirable to keep the overall size of the laptop as small as possible.Furthermore, internal antennas are generally preferred over externalantennas, as externally mounted antennas take up more space and may bedamaged while traveling, etc.

One example of a wireless LAN antenna that is implemented on a PMCIAcard to be inserted in a PMCIA slot of a laptop computer is disclosed inU.S. Pat. No. 6,031,503 to Preiss, II et al. The antenna assemblyincludes two folded, U-shaped antennas, which may be dipoles or slotradiators, that are disposed orthogonally to one another to providepolarization diversity. Polarization diversity means that signals aretransmitted and received on two different polarizations to increase thelikelihood that the signal is received. Signals are carried to and fromthe antenna by microstrip feed lines. The microstrip lines are placedoff center along each antenna slot to establish an acceptable impedancematch for the antenna, and the feed lines are coupled to thecommunications card by coaxial cables.

There is an increasing trend toward using other portable, handheldcommunications devices in wireless LANs which are even smaller thanlaptops, such as personal digital assistants (PDAs), for example.Accordingly, with even more restrictive space constraints for suchhandheld devices, there is a need for antennas which are appropriatelysized for such applications yet still provide desired performancecharacteristics.

SUMMARY OF THE INVENTION

In view of the foregoing background, it is therefore an object of thepresent invention to provide a mobile wireless communications devicewith a wireless LAN antenna providing polarization diversity as well asother desired signal characteristics and related methods.

This and other objects, features, and advantages in accordance with thepresent invention are provided by a mobile wireless local area network(LAN) communications device including a polarization diversity wirelessLAN antenna. More particularly, the mobile wireless LAN communicationsdevice may include a portable, handheld housing, and a wireless LANtransceiver carried by the housing. The polarization diversity wirelessLAN antenna may be for cooperating with the wireless LAN transceiver tocommunicate over a wireless LAN. Moreover, the polarization diversitywireless LAN antenna may include a first antenna element coupled to thewireless LAN transceiver having a first shape and a first polarization.The antenna may further include a second antenna element coupled to thewireless LAN transceiver having a second shape different from the firstshape and a second polarization different from the first polarization.

The first and second antenna elements may have different gain patterns,and the different gain patterns may have a substantially equal main lobegain. Further, the first and second polarizations may be substantiallyorthogonal to one another. At least one of the first and second antennaelements may include a feed branch and a loop branch having a first endcoupled to the feed branch, a second end adjacent the feed branch andseparated therefrom by a gap, and a loop-back section extending betweenthe first and second ends. More specifically, the feed branch mayinclude first and second feed points. The first end of the loop branchmay be coupled to the first feed point, and the second end of the loopbranch may be adjacent the second feed point. Also, the loop-backsection of the loop branch may include at least one arcuate portion.

A circuit board may be carried by the housing having first and secondopposing major surfaces. The first and second antenna elements may beplanar conductive elements on the first major surface of the circuitboard. In addition, a matching network may be coupled between thewireless LAN transceiver and the at least one of the first and secondantenna elements. The mobile wireless LAN communications device may alsoinclude a cellular transceiver carried by the portable, handheldhousing, and a cellular antenna for cooperating with the cellulartransceiver to communicate over a cellular communications network.

A wireless LAN communications method aspect of the invention may includeproviding a polarization diversity wireless LAN antenna, such as the onedescribed briefly above, and communicating signals over a wireless LANvia the first antenna element at a first polarization, and via thesecond antenna element at a second polarization different from the firstpolarization.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is schematic block diagram of a wireless local area network (LAN)including a mobile wireless communications device in accordance with thepresent invention.

FIG. 2 is a more detailed schematic block diagram of the wireless LANtransceiver and polarization diversity antenna of the mobile wirelesscommunications device of FIG. 1.

FIG. 3 is an enlarged rear elevational view of a portion of the mobilewireless communications device of FIG. 1 with the housing removedillustrating the polarization diversity antenna thereof in greaterdetail.

FIG. 4 is an enlarged rear elevational view of an alternate embodimentof the conductors of the polarization diversity antenna of FIG. 3.

FIG. 5 is schematic block diagram of an alternate embodiment of themobile wireless communications device of FIG. 1.

FIG. 6 is a schematic block diagram of an exemplary mobile wirelesscommunications device for use with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likenumbers refer to like elements throughout, and prime and multiple primenotation are used to indicate similar elements in alternate embodiments.

Referring initially to FIG. 1, a wireless local area network (LAN) 20including a mobile wireless communications device 21 in accordance withthe present invention is first described. The wireless LAN 20 alsoillustratively includes a base station 22, and a plurality of accesspoint devices 23 a-23 n, which may be any type of wireless LAN enableddevices (including other mobile wireless communications devices 21), aswill be appreciated by those skilled in the art. While only the singlebase station 22 is shown for clarity of illustration, multiple basestations may be included in some embodiments. The wireless LAN 20 mayoperate in accordance with various wireless LAN standards, such as IEEE802.11/802.11b or Bluetooth, for example, as will also be appreciated bythose skilled in the art.

The mobile wireless communications device 21 illustratively includes aportable, handheld housing 24, and a wireless LAN transceiver 25 carriedby the portable, handheld housing. The device 20 also illustrativelyincludes a polarization diversity wireless LAN antenna 26 forcooperating with the wireless LAN transceiver 25 to communicate over thewireless LAN 20, as will be discussed further below. More particularly,the device 20 may be a PDA-type device in which the wireless LANtransceiver and antenna 26 cooperate to communicate various types ofdata, such as voice data, video data, text (e.g., email) data, Internetdata, etc. over the wireless LAN 20. More specifically, the antenna 26may be used for placing telephone calls over the wireless LAN 20, inwhich case the device 21 may generally take the form or shape of atypical cellular telephone or a cellular-enabled PDA device, forexample.

Turning additionally to FIGS. 2 and 3, the polarization diversitywireless LAN antenna 26 illustratively includes a first antenna element30 coupled to the wireless LAN transceiver 25 at a feed point 31 andhaving a first shape and a first polarization. More particularly, thepeak antenna gain for the first antenna element 30 is directed normal tothe plane thereof, and the polarization of the element is asubstantially vertical polarization, as illustrated with a dashed arrow32.

The antenna 26 also illustratively includes a second antenna element 33coupled to the wireless LAN transceiver 25 at a feed point 34. Thesecond antenna element 33 has a second shape different from the firstshape of the first antenna element 30. Furthermore, the second antennaelement 33 also has a second polarization different from the firstpolarization. In particular, the peak antenna gain for the secondantenna element 33 is also directed normal to the plane thereof, and itspolarization is a substantially horizontal polarization, as illustratedwith a dashed arrow 35. That is, the polarizations of the first andsecond antenna elements 30, 33 are preferably orthogonal to one another,as shown, to provide maximum polarization diversity, as will beappreciated by those skilled in the art. Of course, other arrangementsmay be possible in other embodiments.

The first and second antenna elements 30, 33 may advantageously beimplemented as planar, printed conductive elements on a circuit board36. The circuit board may be mounted on the back side of the device 21(i.e., the side pointing away from the user when holding the device toplace a telephone call) at the top of the device (i.e., adjacent the endof the device with the ear speaker). The first and second antennaelements 30, 33 are shown with hatching to provide greater clarity ofillustration. Moreover, it should also be noted that the illustration ofthe first and second antenna elements 30, 33 shown in FIG. 2 is merelyschematic in nature, with the actual layouts of these elements beingshown in greater detail in FIG. 3. The first antenna element 30illustratively includes a feed branch 37 including the first feed point31, a second feed point 38 which is connected to ground (FIG. 2), and afeed section 39 connected between the first and second feed points.

The first antenna element 30 further illustratively includes a loopbranch 45 having a first end 46 coupled to the feed section 39 adjacentthe first feed point 31. A second end 47 of the loop branch 45 is spacedapart from the feed section 39 by a gap 48, and the second end isadjacent the second feed point 38. A loop-back section 49 extendsbetween the first and second ends 46, 47. More specifically, theloop-back section 49 generally loops in a clockwise direction from thefirst end 46 to the second end 47, as shown. The first antenna element30 thus generally defines a dual feed point, open loop configuration.This configuration advantageously provides increased space savings(i.e., reduced antenna footprint), as will be appreciated by thoseskilled in the art.

The second antenna element 33 also illustratively includes a feed branchdefined by the feed point 34 and a feed section 50. Further, a loopbranch having a first end 51 coupled to the feed section 50, a secondend 52 adjacent the feed branch and separated therefrom by a gap 53, anda loop-back 54 section extending between the first and second ends. Theloop-back section 54 illustratively includes an arcuate portion 55. Thesecond antenna element 33 thus defines a single feed point, open loopelement configuration. Again, this provides space savings, and, thus,reduced antenna footprint.

As will be appreciated by those skilled in the art, various designparameters (e.g., widths, lengths, loop shapes, notches, etc.) may bealtered in the first and second antenna elements 30, 33 to providedifferent signal characteristics. By way of example, the overalldimensions of the first and second antenna elements 30, 33 may be 2 to 3cm high by 2 to 3 cm wide for each element, although other dimensionsmay also be used. The elements 30, 33 preferably operate over a wirelessLAN frequency range of about 2.4 to 2.5 GHz, for example, although otherfrequencies are also possible. Moreover, the coupling between the firstand second elements 30, 33 may also be adjusted to provide desiredperformance characteristics. By way of example, a preferred couplingdistance or gap between the first and second elements 30, 33 may be in arange of about 3 to 7 mm, although other gap distances may also be usedas appropriate for different embodiments.

Because the first and second antenna elements 30, 33 have differentshapes, they will also have different gain patterns, and thusadvantageously provide pattern diversity, as will be appreciated bythose skilled in the art. Moreover, the first and second antennaelements 30, 33 are preferably tuned to have substantially equal mainlobe gain for enhanced performance. Of course, it will be appreciatedthat other antenna element shapes or types may be used in addition tothose noted above. Matching networks 56 a, 56 b may optionally becoupled between the wireless LAN transceiver 25 and the first and secondantenna elements 30, 33, respectively, as shown in FIG. 2, if desired,as will be appreciated by those skilled in the art. Moreover,electromagnetic shielding may be placed over one or both sides of thecircuit board 36 as necessary in certain applications, as will also beappreciated by those skilled in the art.

An alternate embodiment of the polarization diversity wireless LANantenna 26′ is shown in FIG. 4. Here, the first and second feed points31′, 38′ of the first antenna element 30′ are flipped left to right, andthe loop-back section 45′ loops back in a generally counterclockwisedirection, as shown, in contrast to the first antenna element 30. Thesecond antenna element 33 is substantially the same shape as describedabove, except that the end of the loop-back section 54′ near the firstend 51′ has an offset portion 57′.

Turning additionally to FIG. 5, an alternate embodiment of the mobilewireless communications device 21″ further illustratively includes acontroller 60″, a cellular transceiver 61″, and a cellular antenna 62″all carried by the portable, handheld housing 24″. The cellular antenna62″ and cellular transceiver 61″ cooperate to communicate data such asvoice data, text (e.g., email) data, video data, Internet data, etc.,over a cellular communications network 63″, as will be appreciated bythose skilled in the art. The controller 60″ advantageously interfaceswith the wireless LAN and cellular transceivers 25″, 61″ forcoordinating the communication of such data over the wireless LAN 20(FIG. 1) and/or the cellular network 63″. The controller 60″ may beimplemented with a microprocessor and various software modules (e.g.,email module, telephone module, calendar module, address book module,etc.), as will be discussed further below.

A wireless LAN communications method aspect of the invention may includeproviding the polarization diversity wireless LAN antenna 26, asdescribed above, and communicating signals over the wireless LAN 20 viathe first antenna element 30 at a first polarization, and via the secondantenna element 33 at a second polarization different from the firstpolarization. Additional method aspects will be appreciated by thoseskilled in the art from the foregoing description.

Another example of a handheld mobile wireless communications device 1000that may be used in accordance the present invention is furtherdescribed with reference to FIG. 6. The device 1000 includes a housing1200, a keyboard 1400 and an output device 1600. The output device shownis a display 1600, which is preferably a full graphic LCD. Other typesof output devices may alternatively be utilized. A processing device1800 is contained within the housing 1200 and is coupled between thekeyboard 1400 and the display 1600. The processing device 1800 controlsthe operation of the display 1600, as well as the overall operation ofthe mobile device 1000, in response to actuation of keys on the keyboard1400 by the user.

The housing 1200 may be elongated vertically, or may take on other sizesand shapes (including clamshell housing structures). The keyboard mayinclude a mode selection key, or other hardware or software forswitching between text entry and telephony entry.

In addition to the processing device 1800, other parts of the mobiledevice 1000 are shown schematically in FIG. 6. These include acommunications subsystem 1001; a short-range communications subsystem1020; the keyboard 1400 and the display 1600, along with otherinput/output devices 1060, 1080, 1100 and 1120; as well as memorydevices 1160, 1180 and various other device subsystems 1201. The mobiledevice 1000 is preferably a two-way RF communications device havingvoice and data communications capabilities. In addition, the mobiledevice 1000 preferably has the capability to communicate with othercomputer systems via the Internet.

Operating system software executed by the processing device 1800 ispreferably stored in a persistent store, such as the flash memory 1160,but may be stored in other types of memory devices, such as a read onlymemory (ROM) or similar storage element. In addition, system software,specific device applications, or parts thereof, may be temporarilyloaded into a volatile store, such as the random access memory (RAM)1180. Communications signals received by the mobile device may also bestored in the RAM 1180.

The processing device 1800, in addition to its operating systemfunctions, enables execution of software applications 1300A-1300N on thedevice 1000. A predetermined set of applications that control basicdevice operations, such as data and voice communications 1300A and1300B, may be installed on the device 1000 during manufacture. Inaddition, a personal information manager (PIM) application may beinstalled during manufacture. The PIM is preferably capable oforganizing and managing data items, such as e-mail, calendar events,voice mails, appointments, and task items. The PIM application is alsopreferably capable of sending and receiving data items via a wirelessnetwork 1401. Preferably, the PIM data items are seamlessly integrated,synchronized and updated via the wireless network 1401 with the deviceuser's corresponding data items stored or associated with a hostcomputer system.

Communication functions, including data and voice communications, areperformed through the communications subsystem 1001, and possiblythrough the short-range communications subsystem. The communicationssubsystem 1001 includes a receiver 1500, a transmitter 1520, and one ormore antennas 1540 and 1560. In addition, the communications subsystem1001 also includes a processing module, such as a digital signalprocessor (DSP) 1580, and local oscillators (LOs) 1601. The specificdesign and implementation of the communications subsystem 1001 isdependent upon the communications network in which the mobile device1000 is intended to operate. For example, a mobile device 1000 mayinclude a communications subsystem 1001 designed to operate with theMobitex™, Data TAC™ or General Packet Radio Service (GPRS) mobile datacommunications networks, and also designed to operate with any of avariety of voice communications networks, such as AMPS, TDMA, CDMA, PCS,GSM, etc. Other types of data and voice networks, both separate andintegrated, may also be utilized with the mobile device 1000.

Network access requirements vary depending upon the type ofcommunication system. For example, in the Mobitex and DataTAC networks,mobile devices are registered on the network using a unique personalidentification number or PIN associated with each device. In GPRSnetworks, however, network access is associated with a subscriber oruser of a device. A GPRS device therefore requires a subscriber identitymodule, commonly referred to as a SIM card, in order to operate on aGPRS network.

When required network registration or activation procedures have beencompleted, the mobile device 1000 may send and receive communicationssignals over the communication network 1401. Signals received from thecommunications network 1401 by the antenna 1540 are routed to thereceiver 1500, which provides for signal amplification, frequency downconversion, filtering, channel selection, etc., and may also provideanalog to digital conversion. Analog-to-digital conversion of thereceived signal allows the DSP 1580 to perform more complexcommunications functions, such as demodulation and decoding. In asimilar manner, signals to be transmitted to the network 1401 areprocessed (e.g. modulated and encoded) by the DSP 1580 and are thenprovided to the transmitter 1520 for digital to analog conversion,frequency up conversion, filtering, amplification and transmission tothe communication network 1401 (or networks) via the antenna 1560.

In addition to processing communications signals, the DSP 1580 providesfor control of the receiver 1500 and the transmitter 1520. For example,gains applied to communications signals in the receiver 1500 andtransmitter 1520 may be adaptively controlled through automatic gaincontrol algorithms implemented in the DSP 1580.

In a data communications mode, a received signal, such as a text messageor web page download, is processed by the communications subsystem 1001and is input to the processing device 1800. The received signal is thenfurther processed by the processing device 1800 for an output to thedisplay 1600, or alternatively to some other auxiliary I/O device 1060.A device user may also compose data items, such as e-mail messages,using the keyboard 1400 and/or some other auxiliary I/O device 1060,such as a touchpad, a rocker switch, a thumb-wheel, or some other typeof input device. The composed data items may then be transmitted overthe communications network 1401 via the communications subsystem 1001.

In a voice communications mode, overall operation of the device issubstantially similar to the data communications mode, except thatreceived signals are output to a speaker 1100, and signals fortransmission are generated by a microphone 1120. Alternative voice oraudio I/O subsystems, such as a voice message recording subsystem, mayalso be implemented on the device 1000. In addition, the display 1600may also be utilized in voice communications mode, for example todisplay the identity of a calling party, the duration of a voice call,or other voice call related information.

The short-range communications subsystem enables communication betweenthe mobile device 1000 and other proximate systems or devices, whichneed not necessarily be similar devices. For example, the short-rangecommunications subsystem may include an infrared device and associatedcircuits and components, or a Bluetooth communications module to providefor communication with similarly-enabled systems and devices.

Many modifications and other embodiments of the invention will come tothe mind of one skilled in the art having the benefit of the teachingspresented in the foregoing descriptions and the associated drawings.Therefore, it is understood that the invention is not to be limited tothe specific embodiments disclosed, and that modifications andembodiments are intended to be included within the scope of the appendedclaims.

1. A mobile wireless local area network (LAN) communications devicecomprising: a portable, handheld housing; a wireless LAN transceivercarried by said portable, handheld housing; and a wireless LAN antennafor cooperating with said wireless LAN transceiver to communicate over awireless LAN, said wireless LAN antenna comprising a first antennaelement coupled to said wireless LAN transceiver having a first shape,and a second antenna element coupled to said wireless LAN transceiverhaving a second shape different from the first shape; at least one ofsaid first and second antenna elements comprising a feed branch and aloop branch having a first end coupled to said feed branch, a second endadjacent said feed branch and separated therefrom by a gap, and aloop-back section extending between the first and second ends; said feedbranch comprising first and second feed points, the first end of saidloop branch being coupled to the first feed point, and the second end ofsaid loop branch being adjacent the second feed point.
 2. The mobilewireless LAN communications device of claim 1 wherein said first andsecond antenna elements have different gain patterns, and wherein thedifferent gain patterns have a substantially equal main lobe gain. 3.The mobile wireless LAN communications device of claim 1 wherein saidloop-back section of said loop branch comprises at least one arcuateportion.
 4. The mobile wireless LAN communications device of claim 1further comprising: a cellular transceiver carried by said portable,handheld housing; and a cellular antenna for cooperating with saidcellular transceiver to communicate over a cellular communicationsnetwork.
 5. The mobile wireless LAN communications device of claim 1further comprising a circuit board carried by said housing and havingfirst and second opposing major surfaces; and wherein said first andsecond antenna elements comprise planar conductive elements on the firstmajor surface of said circuit board.
 6. The mobile wireless LANcommunications device of claim 1 further comprising a matching networkcoupled between said wireless LAN transceiver and at least one of saidfirst and second antenna elements.
 7. A mobile wireless local areanetwork (LAN) communications device comprising: a portable, handheldhousing; a circuit board carried by said housing; a cellular transceivercarried by said circuit board; a cellular antenna for cooperating withsaid cellular transceiver to communicate over a cellular communicationsnetwork; a wireless LAN transceiver carried by said circuit board; and awireless LAN antenna for cooperating with said wireless LAN transceiverto communicate over a wireless LAN, said wireless LAN antenna comprisinga first antenna element coupled to said wireless LAN transceiver havinga first shape, and a second antenna element coupled to said wireless LANtransceiver having a second shape different from the first shape; saidfirst and second antenna elements comprising planar conductive elementson said circuit board; at least one of said first and second antennaelements comprising a feed branch and a loop branch having a first endcoupled to said feed branch, a second end adjacent said feed branch andseparated therefrom by a gap, and a loop-back section extending betweenthe first and second ends; said feed branch comprising first and secondfeed points, the first end of said loop branch being coupled to thefirst feed point, and the second end of said loop branch being adjacentthe second feed point.
 8. The mobile wireless LAN communications deviceof claim 7 wherein said first and second antenna elements have differentgain patterns, and wherein the different gain patterns have asubstantially equal main lobe gain.
 9. The mobile wireless LANcommunications device of claim 7 wherein said loop-back section of saidloop branch comprises at least one arcuate portion.
 10. The mobilewireless LAN communications device of claim 7 further comprising amatching network coupled between said wireless LAN transceiver and atleast one of said first and second antenna elements.
 11. A wirelesslocal area network (LAN) antenna comprising: a first antenna elementhaving a first shape; and a second antenna element coupled to saidwireless LAN transceiver having a second shape different from the firstshape; at least one of said first and second antenna elements comprisinga feed branch and a loop branch, the loop branch having a first endcoupled to said feed branch, a second end adjacent said feed branch andseparated therefrom by a gap, and a loop-back section extending betweenthe first and second ends; said feed branch comprising first and secondfeed points, the first end of said loop branch being coupled to thefirst feed point, and the second end of said loop branch being adjacentthe second feed point.
 12. The wireless LAN antenna of claim 11 whereinsaid first and second antenna elements have different gain patterns, andwherein the different gain patterns have a substantially equal main lobegain.
 13. The wireless LAN antenna of claim 11 wherein said loop-backsection of said loop branch comprises at least one arcuate portion. 14.A wireless local area network (LAN) communications method comprising:providing a wireless LAN antenna comprising a first antenna elementhaving a first shape, and a second antenna element having a second shapedifferent from the first shape; at least one of the first and secondantenna elements comprising a feed branch and a loop branch, the loopbranch having a first end coupled to the feed branch, a second endadjacent the feed branch and separated therefrom by a gap, and aloop-back section extending between the first and second ends; the feedbranch comprising first and second feed points, the first end of theloop branch being coupled to the first feed point, and the second end ofthe loop branch being adjacent the second feed point; and communicatingsignals over a wireless LAN via the first and second antenna elements.15. The method of claim 14 wherein the first and second antenna elementshave different gain patterns, and wherein the different gain patternshave a substantially equal main lobe gain.
 16. The method of claim 14wherein the loop-back section of the loop branch comprises at least onearcuate portion.